Carburetor



Aug. 17, 1926. 1,596,738

' G. KlNGSTON CARBURETOR Filed Feb. 19, 1923 2 Sheets-Sheet 1 4/ GEOKQEMNi- I ray Aug. 17,1926;

G. KINGSTON CARBURETDR Filed Fb. 19. 1923 2 Sheets-Sheet 2 Patented Aug.17, 1926.

UNITED STATES.

G OR E, KINGSTON IWKOMP am-we.

CARBURETOR.

Application filed February 19, 1923. Serial No. 619,893.

This invention relates to a carburetor and particularly to a carburetorwhich is provided with effective and conveniently accessible low speedadjusting means.

Variations in the characteristics of individual motors requires thatfuel mixture of different quality and quantity be provided to assureeflicient operation thereof at low speeds. It is also often desirablethat the low speed adjustments be changed after the carburetor. isinstalled because of changes in weather. conditions or in the fuel used.

It is an. important object therefore of this invention toprovide acarburetor wherein an adjustment for proper; low speed operation may bequickly and conveniently made.

It is a further important object of this invention to, provide acarburetor wherein a plurality of adjusting means which are separatelyoperable from the outside of the carburetor extend to a common pointwithin the carburetor.

Other and further important objects of the present invention willbeapparent'from the disclosures i i the. specification the acc mpa y saw Y The invention (in a preferred form) is shown on: the, drawings andhereinafter more a lyec e d;

n he raw g Ei gure his; atop, plan View of a carburetor embcdyingthe,principles of the present m QILt QI Figure 2 is a side elevation of thecarburetor; i

Figure 3 is a section on the line 3-3 of u e 2, w t bai in' evat q F -gre s e ti Q t e lin H of Figure, 1;, looking the. direction indicated bythe arrows and with parts shown in elevation.

Figure 5 is, a section on the line H of Figure 1 looking in thedirection opposite to that indicated by the, arrows andwith parts shownin elevation.

As shown on the drawings:

The, reference numeral 1 indicates a cast metal carburetor casing whichis cored to provide an air inlet 2, controlled by a usual choke valve 2a mixing chamber 3 and a mixture outlet 4. A usual flange 5 is formedon, the. casing 1 adjacent the mixture outlet t to afford a connectionwith an in take manifold; and the flow of fuel mixture through themixture outlet is controlled in the usual mannerby a butterfly throttlevalve 6 which is pivoted in the casing 1 and operable from the outsidethereof by a usual lever 7 I Extending downwardly from the floor of themixing chamber is an integral project ing member 8 which has its lowerend reduced and threaded as indicated at 9, and engaged over saidreduced and threaded portion 9 is 'a cup member 10 which affords asupply chamber for liquid fuel and the up.- per end of which abuts aseat formed in a suitable flange 11 which is integral with the casing 1.Said cup member 10 is held in adjusted position by. means of a nut 12engaged outside the same on the threaded portion 9, the tightening ofsaid nut 12 forcing the inside. of said cup member 10against a gasket 13interposed between. said cup member and the shoulder formed on themember 8 at the junction thereof with the reducedportion 9, Liquid fuelis supplied to the. fuel chamber afforded by the cup. member 10 througha passage 14 formed in the casing, 1 and communicating with" a suitablefuel connection 15 leading to a source of supply. The flow of fuelthrough the passage 14 is regulated by a valve 16 which is controlled inthe usual manner by a float 17- mounted inside, the cup member 10. Anintegral dividing wall 18 is formed in the casing 1 betwen the mix ingchamber 3 and the mixture outlet 4, and the flow of fuel mixture,through a passage in said dividing wall is controlled by a pivoted;weighted valve 19 which seats on a flange 20, formed in said dividingwall around" the opening therein, and; which is adapted to be liftedfrom its seat by the flow of fuel mixture, the opening movement of thevalve being limited by the con- 'tactof a portion 21 thereon witha boss22 integral with the casing 1 and projecting into the mixture outlet 4:.

Liquidfuel is admitted to. the mixing chamber from the fuel supplychamber af forded by the cup member 10. through a passage 23 which isformed in the member 8 and the lower end of which opens into said fuelsupply chamber. The flow of liquid fuel through said passage 23 1scontrolled bya needle valve 24 which 1s adjustably mounted in aninternally threaded to the upper end thereof.

As will be noted of Figures 3, at and 5, the needle valve 2a ispositioned at an angle relative to the vercilitate' the rotation of saidstem 36 from the outside of the carburetor, the upper tical axis of theCarburetor and extends through a passage formed in the wall 18. Theupper end of the passage to receive a tubular member 27 which is open ateach end and the axis of which converges to meet the axis of the needlevalve 24. As will be noted inFigure 5, said open-ended tubular member 27is slotted at its upper end'to allow the needle valve 24; to be engagedtherethrough and to enter the upper end of the passage 23. v

In order to obviate the possibility of flooding the mixing chamber 3 anoverflow passage 29 is formed in the member 8 leading to'the outside ofthe carburetor and having an open-end tube '30 secured in its upper endand projecting into themixing'chamber for a short distance above the endof the tubular member 27. A usual drain valve 31 is secured in the floorof the cup member 10 for the purposeof draining the fuel supply chamberwhen desired.

Coaxial with thetubular member 271 and having its lower end separated ashort distance from the upper end of said tubular member is a tubularmember 32 which is threaded at 33 for engagement with a threaded openingin the wall 18 and said tubular member 32 is provided atits upper endwith a plurality of apertures 35 opening into the mixture outlet 4.Secured tov or integral with the upper end of the tubular member 32 is astem outwardly'through and is rotatably mounted in a-sleeve nut 37 whichis threaded in the upper side of the casing 1. In order to faend thereofis provided with a knurled adjusting nut 38. It will be noted that thetubular member 32 affords a 'by-pass between the mixing chamber 3 andthe mixture outlet t around the valve 19 and said by-pass affords apath'for the flow of fuel mixture when the engine is idlingor running atlow speeds." The quality of the fuel mixture flowing through the tubularmember 32 may be adjusted said tubular member, ment being effectedthrough the 'stem36 and adjusting nut-38L It will, of course,- beapparent that as the lower end of' he tubular member 32 is moved intoproximity with the upper end of the tubular member 27, less air will beadmitted to the by-pass and a richer mixture for such axial adj 11stfrom an examination 23 is enlarged 36 which extends a 1. I am aware byrotation thereof member 24, under these conditions more air beingadmitted and a leaner idling or low speed mixture being provided, themixture in each case being discharged into the mix ure outlet athroughthe apertures 35.

-:It will be apparent from the foregoing that this invention provides acarburetor structure wherein an accurate adjustment for low speedoperating conditions may be conveniently made from the outside of thecarburetor. This adjustment may be effected without in any waydisturbing the high speed adjustment which is made by properlypositioning the needle valve 2&, and the provision thereof makespossible the accurate adaptationof the carburetor to individual motorshaving varying operating characteristics. In the operation. of thecarburetor, at low or idling speeds the automatic valve 19 remainsseateddue to its own weight and the fuel and air mixture requirements ofthe engine are met by the flow through the bypass tube 32 andport 35. Itwill be evident that screwing down this tube will reduce the area forthe admission of air between the tubes 27 and 32, without affecting thefuel supply, thereby effecting the production of a richer mixture. Asthe throttle. is opened the suction therebeneath reaches a pointsufficient to lift the weighed .yalve l9, opening up a large airvpassagewhich will draw fuel over the edge of the tube 27 in addition to thatfuel carried up the tube 32, so'that for high speed (the fuel may becontrolled by the valve is adjusted for'high speed requirements and thetube 32 is adjusted to care for the low speed requirements, therlatteradjustment having only the high speed adjustment.

It will be noted that the adjusting means Ja-re. simple andmay beeconomically manufactured, and that they do not in any way interferewith the normal operation of the carburetor. I

that numerous details of construction may bei varied through a widerange without departing from the principles of this invention, and Itherefore do not purpose; limiting the patent granted, otherwise thannecessitated by the prior art. by axially adjusting I claim as myinvention; V 1. Ina carburetor, a mixing chamber, a fuel inlet, an airinlet, a mixture outlet," a throttle, an automatic valve between themixing chamber and the mixture outlet, a

tube extending; from the mixing chamber to the mixture outlet andforming a'by-pass around said valve, said tube having a plurality ofapertures in the portion thereof a slight effect on extending into themixture outlet, and means for adjusting the tube longitudinally from theoutside of the carburetor.

2. In a carburetor, amixing chamber, a fuel inlet, a tube surroundingthe fuel inlet, an air inlet, a mixture outlet, a throttle valve, anautomatic Valve between the mixing chamber and the mixture outlet, asecond tube coaxial with the first tube and affording a by-pass aroundsaid automatic valve, and means for adjusting the position of saidsecond tube relative to the first tube from the outside of thecarburetor.

3. In a carburetor, an air inlet, a mixing chamber, a mixture outlet, afuel inlet, a slotted tube surrounding the fuel inlet, a needle valveextending from the outside of the carburetor through the slot in saidtube and acting to control the flow of fuel from said fuel inlet, asecond tube adjustable from the outside of the carburetor and coaxialwith said first tube, said second tube opening into said mixture outletand said mixing chamber.

4:. In a carburetor, an air inlet, a mixing, chamber, a mixture outlet,a fuel inlet, a tube surrounding the fuel inlet, a needle valveextending from the outside of the carburetor through an opening in saidtube and acting to control the flow of fuel from said fuel inlet, asecond tube adjustable from the outside of the carburetor and coaxialwith said first tube, said second tube opening into said mixture outletand said mixing chamber.

In testimony whereof I have hereunto subscribed my name.

GEORGE KINGSTON.

